This invention relates in general to imaging devices and, more particularly, to optical scanning of media configurations in a printer for controlling imaging in the printer relative to the characterized media configurations.
Imaging devices, such as laser printers, ink jet printers, copiers, facsimile machines and the like, typically include a media processing path for enabling the transfer of a sheet of media through the device. Generally, the media is picked from an input bin, transferred to an imaging station where the image is developed, and then passed on to an output bin. Often, sensors are disposed in the media processing path for detecting when the media is picked, such as by detecting a leading edge of the media, or for detecting other peripheral edges of the media to enable the imaging system to adjust for media size and skew within certain pre-defined parameters. U.S. Pat. Nos. 5,127,752 and 4,538,905, incorporated in full herein by reference, teach exemplary systems employing media periphery edge detect sensors for enabling image alignment to the media being transferred in the processing path.
One drawback with conventional media periphery sensing systems is that they are typically limited in design to work only with conventional predetermined media sizes such as 8xc2xdxc3x9711 inch xe2x80x9cletterxe2x80x9d sheets, 8xc2xdxc3x9714 inch xe2x80x9clegalxe2x80x9d sheets, A4 sized sheets, envelopes, etc. Thus, any custom defined media size and/or shape that departs from the norm may not be detected, handled or imaged properly by the imaging device. For example, if a hexagonal sided or other odd shaped media is transferred into a media processing path (assuming the device/path could handle it using, for example, electronic tacking of the media to a transfer belt), then the correct size and shape of the xe2x80x9coddxe2x80x9d shaped media is simply not properly detected. Rather, a known default size is generally used. As such, undesired imaging outside of the actual peripheral boundaries of the media may occur, thereby causing wasteful, messy and improper toner development or ink deposits in the system.
Additionally, conventional sensing systems do not detect or account for voids within the periphery of the media being processed. For example, if a hole-punched sheet of xe2x80x9cletterxe2x80x9d size media is passed through the device for imaging purposes, the holes are not recognized and image development is attempted as if the sheet were whole and did not have the holes. In this context, assuming imaging is to occur at the location of the holes, improper attempted imaging in the area of the holes (voids) will also cause wasteful, messy and improper toner development or ink deposits in the system.
Accordingly, an object of the present invention is to enable full media mapping in an imaging device to ensure image development only on the media.
According to principles of the present invention in a preferred embodiment, a method of imaging in an imaging device includes optically mapping a surface area of a media to be imaged by the imaging device and controlling the imaging device based on the mapped surface area such that imaging occurs only on the media. Preferably, the surface area includes substantially an entire area of the media associated with at least one given scan line of the imaging device. Mapping of the surface area includes identifying peripheral bounds of the media and voids, if any, in the media. In a laser printer employing one embodiment of the present invention, image development is controlled by enabling and disabling the laser beam based on image data in coordination with the mapped surface area of the media.
According to further principles, an imaging device such as a laser printer, copier or ink jet printer includes components for enabling the above described method.
Other objects, advantages, and capabilities of the present invention will become more apparent as the description proceeds.